fix(git): fixed branch detection, get target commit from origin and always checkout a tag or commit so we dont need to use git merge

Author: folke

lua/lazy/manage/git.lua

@@ -51,41 +51,54 @@ function M.get_versions(repo, spec)
 end
 
 ---@param plugin LazyPlugin
----@return {branch:string, commit?:string}?
+---@return string?
 function M.get_branch(plugin)
   if plugin.branch then
-    return {
-      branch = plugin.branch,
-      commit = M.ref(plugin.dir, "heads/" .. plugin.branch),
-    }
+    return plugin.branch
   else
+    -- we need to return the default branch
+    -- Try origin first
     local main = M.ref(plugin.dir, "remotes/origin/HEAD")
     if main then
       local branch = main:match("ref: refs/remotes/origin/(.*)")
       if branch then
-        return {
-          branch = branch,
-          commit = M.ref(plugin.dir, "heads/" .. branch),
-        }
+        return branch
       end
     end
+
+    -- fallback to local HEAD
+    main = assert(Util.head(plugin.dir .. "/.git/HEAD"))
+    return main and main:match("ref: refs/heads/(.*)")
+  end
+end
+
+-- Return the last commit for the given branch
+---@param repo string
+---@param branch string
+---@param origin? boolean
+function M.get_commit(repo, branch, origin)
+  if origin then
+    -- origin ref might not exist if it is the same as local
+    return M.ref(repo, "remotes/origin", branch) or M.ref(repo, "heads", branch)
+  else
+    return M.ref(repo, "heads", branch)
   end
 end
 
 ---@param plugin LazyPlugin
 ---@return GitInfo?
 function M.get_target(plugin)
-  local branch = M.get_branch(plugin) or M.info(plugin.dir)
+  local branch = assert(M.get_branch(plugin))
 
   if plugin.commit then
     return {
-      branch = branch and branch.branch,
+      branch = branch,
       commit = plugin.commit,
     }
   end
   if plugin.tag then
     return {
-      branch = branch and branch.branch,
+      branch = branch,
       tag = plugin.tag,
       commit = M.ref(plugin.dir, "tags/" .. plugin.tag),
     }
@@ -95,19 +108,19 @@ function M.get_target(plugin)
     local last = Semver.last(M.get_versions(plugin.dir, version))
     if last then
       return {
-        branch = branch and branch.branch,
+        branch = branch,
         version = last,
         tag = last.tag,
         commit = M.ref(plugin.dir, "tags/" .. last.tag),
       }
     end
   end
   ---@diagnostic disable-next-line: return-type-mismatch
-  return branch
+  return { branch = branch, commit = M.get_commit(plugin.dir, branch, true) }
 end
 
-function M.ref(repo, ref)
-  return Util.head(repo .. "/.git/refs/" .. ref)
+function M.ref(repo, ...)
+  return Util.head(repo .. "/.git/refs/" .. table.concat({ ... }, "/"))
 end
 
 return M

lua/lazy/manage/lock.lua

@@ -29,8 +29,7 @@ function M.update()
     if not plugin._.is_local and plugin._.installed then
       local info = assert(Git.info(plugin.dir))
       if not info.branch then
-        local branch = assert(Git.get_branch(plugin))
-        info.branch = branch.branch
+        info.branch = assert(Git.get_branch(plugin))
       end
       info.commit = info.commit
       -- f:write(([[  [%q] = { branch = %q, commit = %q },]]):format(name, info.branch, info.commit) .. "\n")

lua/lazy/manage/task/git.lua

@@ -30,6 +30,7 @@ M.log = {
     elseif opts.check then
       local info = assert(Git.info(self.plugin.dir))
       local target = assert(Git.get_target(self.plugin))
+      assert(target.commit, self.plugin.name .. " " .. target.branch)
       table.insert(args, info.commit .. ".." .. target.commit)
     else
       vim.list_extend(args, opts.args or Config.options.git.log)
@@ -76,22 +77,23 @@ M.clone = {
   end,
 }
 
+-- setup origin branches if needed
+-- fetch will retrieve the data
 M.branch = {
   skip = function(plugin)
     if not plugin._.installed or plugin._.is_local then
       return true
     end
     local branch = assert(Git.get_branch(plugin))
-    return branch and branch.commit
+    return Git.get_commit(plugin.dir, branch)
   end,
   run = function(self)
-    local branch = assert(Git.get_branch(self.plugin))
     local args = {
       "remote",
       "set-branches",
       "--add",
       "origin",
-      branch.branch,
+      assert(Git.get_branch(self.plugin)),
     }
 
     self:spawn("git", {
@@ -101,6 +103,7 @@ M.branch = {
   end,
 }
 
+-- fetches all needed origin branches
 M.fetch = {
   skip = function(plugin)
     return not plugin._.installed or plugin._.is_local
@@ -121,6 +124,8 @@ M.fetch = {
   end,
 }
 
+-- checkout to the target commit
+-- branches will exists at this point, so so will the commit
 M.checkout = {
   skip = function(plugin)
     return not plugin._.installed or plugin._.is_local
@@ -131,21 +136,24 @@ M.checkout = {
     local info = assert(Git.info(self.plugin.dir))
     local target = assert(Git.get_target(self.plugin))
 
-    -- if the plugin is locked and we did not just clone it,
+    -- if the plugin is pinned and we did not just clone it,
     -- then don't update
     if self.plugin.pin and not self.plugin._.cloned then
       target = info
     end
 
     local lock
     if opts.lockfile then
+      -- restore to the lock if it exists
       lock = Lock.get(self.plugin)
       if lock then
         ---@diagnostic disable-next-line: cast-local-type
         target = lock
       end
     end
 
+    -- dont run checkout if target is already reached.
+    -- unless we just clones, since then we won't have any data yet
     if not self.plugin._.cloned and info.commit == target.commit and info.branch == target.branch then
       self.plugin._.updated = {
         from = info.commit,
@@ -165,8 +173,8 @@ M.checkout = {
       table.insert(args, "tags/" .. target.tag)
     elseif self.plugin.commit then
       table.insert(args, self.plugin.commit)
-    elseif target.branch then
-      table.insert(args, target.branch)
+    else
+      table.insert(args, target.commit)
     end
 
     self:spawn("git", {